The average number of calls received by a switchboard in a 30-minute period is 15

a. What is the probability that between 10:00 and 10:30 the switchboard will receive exactly 10 calls?b. What is the probability that between 10:00 and 10:30 the switchboard will receive more than 9 calls but fewer than 15 calls?c What is the probability-that between 10:00 and 10:30 the switchboard will receive fewer than 7 calls?

Not really Sure how to set up.

Aug 2nd 2008, 09:34 AM

TKHunny

The Poisson Probability Distribution is very straight-forward. Simply calculate the desired values.

As long as we are sticking witht he half-hour period already defined, just go with it. No adjustment is required.